The present invention relates generally to dishwasher machines having dishwasher tubs, and more particularly to such a tub which attenuates dishwashing noise.
Conventional dishwasher machines automatically wash dishes in a dishwasher tub which typically is a light-weight plastic tub for cost, durability, and corrosion reasons. Such dishwasher machines produce noise including noise produced from the dishwashing operation inside the dishwasher tub. The conventional method for attenuating sound transmission through a plate-like structure is to increase its mass (or, more precisely, its surface density measured in units of mass per area). It is noted that increasing the bending stiffness makes the structure more conductive to sound, while making it less stiff will degrade the tub's structural integrity. The addition of mass in the form of thicker tub walls or added patches of damping material will attenuate sound an additional 6 dB for each doubling of the mass. This rapidly makes the tub heavier and more expensive for modest improvements in sound attenuation. A blanket of sound absorption material (e.g., loose fiberglass insulation) around the outside of the dishwasher tub in the space between the tub and the surrounding kitchen counter/cabinets will also attenuate noise. What is needed is a dishwasher tub for a dishwasher machine which further attenuates unwanted dishwashing noise.